Interpret to a complex plane!
$\newcommand{\Re}{\operatorname{Re}}\newcommand{\Im}{\operatorname{Im}}$The question is:
Interpret $$ \Re z + \Im z = 1 $$ geometrically in the complex plane.
Writing $z = x + yi$, the condition $\Re z + \Im z = 1$ becomes $x + y = 1$.
Now should we rearrange $y = 1 - x$ and say it is a line that crosses the two coordinates $(0, 1)$ and $(1, 0)$? Or am I way off on this one? :/
You are spot-on. This is simply the line in the plane $x + y = 1$.